Why: The specs branch merged, but its merge subject lacks the default branch tail, so the close scan did not select this card.
Evidence: merge d40d1c2 of PR 501 is in origin/main and its tree matches head 72763c9. Backfill follows the card_backfill format.
Impact: One task card moved to .task/archive with status backfilled. No code change. Second-instance writes stay closed.
Refs: .task/archive/feature-u7-release-roadmap.md
Co-authored-by: Cursor <cursoragent@cursor.com>